Answer:
Option A - The population mean is
Confidence interval is (3.153,166.047).
Step-by-step explanation:
Given : Assume that the population has a normal distribution
n=30, x=84.6, s=10.5, 90% confidence.
To find : Use the given degree of confidence and sample data to construct a confidence interval for the population mean mu?
Solution :
First we apply z-score formula,
Where, x is the sample mean x=84.6
s is the standard deviation s=10.5
n is the number of sample n=30
is the population mean
z is the score value, at 90% z=1.645
Substitute all the values in the formula,
So, The population mean is
Therefore, Option A is correct.
Now, Apply confidence interval formula
Therefore, Confidence interval is (3.153,166.047).